merge: 合并 K95 频道切换加载修复

lib/core/data/services/home_feed_controller.dart

@@ -10,28 +10,31 @@ import '../../../pages/home/home_feed_channel.dart';
 
 /// 首页内容类型频道状态：每频道独立缓存、刷新和游标分页。
 class HomeFeedController extends ChangeNotifier {
-  HomeFeedController(this._repository)
-    : _states = {
-        for (final channel in HomeFeedChannel.values)
-          channel: _ChannelFeedState(),
-      };
+  HomeFeedController(
+    this._repository, {
+    this.requestTimeout = defaultRequestTimeout,
+  }) : _states = {
+         for (final channel in HomeFeedChannel.values)
+           channel: _ChannelFeedState(),
+       };
 
   static const int pageSize = 10;
+  static const Duration defaultRequestTimeout = Duration(seconds: 10);
 
   final CatalogRepository _repository;
+  final Duration requestTimeout;
   final Map<HomeFeedChannel, _ChannelFeedState> _states;
   HomeFeedChannel _channel = HomeFeedChannel.recommend;
-  String? _lastError;
   bool _disposed = false;
 
   HomeFeedChannel get channel => _channel;
-  String? get lastError => _lastError;
+  String? get lastError => _state(_channel).lastError;
   List<Drama> get dramas => _state(_channel).dramas;
   String? get cursor => _state(_channel).cursor;
   bool get hasMore => _state(_channel).hasMore;
   bool get loaded => _state(_channel).loaded;
   bool get loadingMore => _state(_channel).loadingMore;
-  bool get loadingFirstPage => !loaded;
+  bool get loadingFirstPage => !loaded && _state(_channel).loading;
 
   /// 用首页聚合接口打平的数据填充推荐首屏，不发起网络请求。
   void seedRecommend(List<Drama> dramas) {
@@ -42,27 +45,41 @@ class HomeFeedController extends ChangeNotifier {
       ..cursor = null
       ..hasMore = false
       ..loaded = true
-      ..loadingMore = false;
-    _lastError = null;
-    if (_channel == HomeFeedChannel.recommend) _notify();
+      ..loading = false
+      ..loadingMore = false
+      ..lastError = null
+      ..inFlight = null;
+    _notifyIfCurrent(HomeFeedChannel.recommend);
   }
 
-  /// 同步切到目标频道；有缓存先渲染，再在后台静默刷新。
+  /// 同步切到目标频道；有缓存先渲染，无缓存时复用或等待在飞请求。
   Future<void> selectChannel(HomeFeedChannel next) async {
     if (next == _channel) return;
     _channel = next;
-    _lastError = null;
     _notify();
     final state = _state(next);
     if (state.dramas.isNotEmpty) {
-      unawaited(_refresh(next, keepData: true));
-    } else {
-      await _loadFirst(next);
+      if (!state.loading) {
+        unawaited(_refresh(next, keepData: true));
+      }
+      return;
     }
+    if (state.loading) {
+      final inFlight = state.inFlight;
+      if (inFlight != null) await inFlight;
+      return;
+    }
+    await _refresh(next, keepData: false);
   }
 
   /// 刷新当前频道，失败时保留旧数据。
-  Future<bool> refreshCurrent() => _refresh(_channel, keepData: true);
+  Future<bool> refreshCurrent() async {
+    final state = _state(_channel);
+    if (state.loading) {
+      return await state.inFlight ?? false;
+    }
+    return _refresh(_channel, keepData: true);
+  }
 
   /// 加载当前频道下一页并去重追加。
   Future<void> loadMore() async {
@@ -71,14 +88,16 @@ class HomeFeedController extends ChangeNotifier {
     if (!state.hasMore || state.loadingMore || state.cursor == null) return;
     final seq = ++state.requestSeq;
     state.loadingMore = true;
-    _notify();
+    _notifyIfCurrent(channel);
     try {
-      final page = await _repository.fetchFeed(
-        types: channel.apiTypes,
-        cursor: state.cursor,
-        size: pageSize,
-      );
-      if (!_accept(channel, seq)) return;
+      final page = await _repository
+          .fetchFeed(
+            types: channel.apiTypes,
+            cursor: state.cursor,
+            size: pageSize,
+          )
+          .timeout(requestTimeout);
+      if (!_acceptSequence(channel, seq)) return;
       final seen = state.dramas.map((drama) => drama.id).toSet();
       final appended = page.dramas
           .where((drama) => seen.add(drama.id))
@@ -87,62 +106,78 @@ class HomeFeedController extends ChangeNotifier {
         ..dramas = List.unmodifiable([...state.dramas, ...appended])
         ..cursor = page.nextCursor
         ..hasMore = page.hasMore
-        ..loaded = true;
-      _lastError = null;
+        ..loaded = true
+        ..lastError = null;
     } catch (error) {
-      if (_accept(channel, seq)) _lastError = error.toString();
+      if (_acceptSequence(channel, seq)) {
+        state.lastError = error.toString();
+      }
     } finally {
       state.loadingMore = false;
-      if (_acceptChannel(channel)) _notify();
+      _notifyIfCurrent(channel);
     }
   }
 
-  Future<void> _loadFirst(HomeFeedChannel channel) async {
+  Future<bool> _refresh(HomeFeedChannel channel, {required bool keepData}) {
     final state = _state(channel);
-    state.loaded = false;
-    await _refresh(channel, keepData: state.dramas.isNotEmpty);
+    final operation = _performRefresh(channel, keepData: keepData);
+    state.inFlight = operation;
+    unawaited(_clearInFlight(state, operation));
+    return operation;
   }
 
-  Future<bool> _refresh(
+  Future<bool> _performRefresh(
     HomeFeedChannel channel, {
     required bool keepData,
   }) async {
     final state = _state(channel);
     final seq = ++state.requestSeq;
-    _lastError = null;
-    if (_acceptChannel(channel)) _notify();
+    state
+      ..loading = true
+      ..lastError = null;
+    _notifyIfCurrent(channel);
     try {
-      final page = await _repository.fetchFeed(
-        types: channel.apiTypes,
-        size: pageSize,
-      );
-      if (!_accept(channel, seq)) return false;
+      final page = await _repository
+          .fetchFeed(types: channel.apiTypes, size: pageSize)
+          .timeout(requestTimeout);
+      if (!_acceptSequence(channel, seq)) return false;
       state
         ..dramas = List.unmodifiable(page.dramas)
         ..cursor = page.nextCursor
         ..hasMore = page.hasMore
         ..loaded = true
-        ..loadingMore = false;
-      _lastError = null;
-      _notify();
+        ..loading = false
+        ..lastError = null;
+      _notifyIfCurrent(channel);
       return true;
     } catch (error) {
-      if (!_accept(channel, seq)) return false;
+      if (!_acceptSequence(channel, seq)) return false;
       if (!keepData) state.dramas = const [];
-      state.loaded = true;
-      _lastError = error.toString();
-      _notify();
+      state
+        ..loaded = true
+        ..loading = false
+        ..lastError = error.toString();
+      _notifyIfCurrent(channel);
       return false;
     }
   }
 
+  Future<void> _clearInFlight(
+    _ChannelFeedState state,
+    Future<bool> operation,
+  ) async {
+    await operation;
+    if (identical(state.inFlight, operation)) state.inFlight = null;
+  }
+
   _ChannelFeedState _state(HomeFeedChannel channel) => _states[channel]!;
 
-  bool _accept(HomeFeedChannel channel, int seq) =>
-      !_disposed && channel == _channel && _state(channel).requestSeq == seq;
+  bool _acceptSequence(HomeFeedChannel channel, int seq) =>
+      !_disposed && _state(channel).requestSeq == seq;
 
-  bool _acceptChannel(HomeFeedChannel channel) =>
-      !_disposed && channel == _channel;
+  void _notifyIfCurrent(HomeFeedChannel channel) {
+    if (!_disposed && channel == _channel) _notify();
+  }
 
   void _notify() {
     if (!_disposed) notifyListeners();
@@ -160,6 +195,9 @@ class _ChannelFeedState {
   String? cursor;
   bool hasMore = true;
   bool loaded = false;
+  bool loading = false;
   bool loadingMore = false;
+  String? lastError;
   int requestSeq = 0;
+  Future<bool>? inFlight;
 }

lib/pages/player/player_logic.dart

@@ -102,6 +102,13 @@ class PlayerLogic extends ChangeNotifier {
   bool _disposed = false;
   PlayerFactory? _sessionFactory;
   PlaybackCoordinator? _sessionCoordinator;
+  int feedRevision = 0;
+  List<Drama> _latestFeed = const [];
+  String? _latestKeepDramaId;
+  bool _latestResetToFirst = false;
+  bool _feedUpdateRunning = false;
+  bool _hasPendingFeed = false;
+  Future<void> _feedUpdateFuture = Future<void>.value();
 
   /// [start] 是否已经跑过：没跑过时 session/pages 还是 late 未初始化，
   /// dispose 不能直接碰它们（例如页面构建失败或纯逻辑测试）。
@@ -111,6 +118,9 @@ class PlayerLogic extends ChangeNotifier {
 
   bool get chromeHidden => immersive;
 
+  /// 最近一次 feed 更新流程完成；测试和页面退出可等待它结束。
+  Future<void> get feedUpdateSettled => _feedUpdateFuture;
+
   /// 当前 PageView 对应用户正在观看的短剧 id，尚未起播时为 null。
   String? get currentDramaId {
     if (!_started || visibleIndices.isEmpty) return null;
@@ -173,38 +183,26 @@ class PlayerLogic extends ChangeNotifier {
     unawaited(selectEpisode(initialIndex));
   }
 
-  /// 原地替换首页 feed 队列；频道变化时重置到第 1 个，刷新时尽量保留当前剧。
-  void updateFeed(List<Drama> dramas, {String? keepDramaId}) {
-    final currentId = currentDramaId;
-    final nextQueue = PlaybackQueue.home(List<Drama>.unmodifiable(dramas));
-    final nextVisible = List<int>.generate(nextQueue.length, (index) => index);
-    final nextEpisodes = [for (final entry in nextQueue.entries) entry.episode];
-    feedDramas = List<Drama>.unmodifiable(dramas);
-    queue = nextQueue;
-    visibleIndices = nextVisible;
-    if (dramas.isNotEmpty) pageDrama = dramas.first;
-    if (!_started) return;
-    if (nextQueue.length == 0) {
-      session.setRouteVisible(false);
-      notify();
+  /// 串行替换首页 feed 队列；频道变化时重置到第 1 个，刷新时尽量保留当前剧。
+  void updateFeed(
+    List<Drama> dramas, {
+    String? keepDramaId,
+    bool resetToFirst = false,
+  }) {
+    feedRevision++;
+    pageRequest++;
+    _latestFeed = List<Drama>.unmodifiable(dramas);
+    _latestKeepDramaId = keepDramaId;
+    _latestResetToFirst = resetToFirst;
+    _hasPendingFeed = true;
+    if (!_started) {
+      feedDramas = _latestFeed;
       return;
     }
-    final keepIndex = keepDramaId != null && keepDramaId == currentId
-        ? nextQueue.entries.indexWhere((entry) => entry.drama.id == keepDramaId)
-        : -1;
-    if (keepIndex >= 0 && session.active != null) {
-      sessionEpisodes
-        ..clear()
-        ..addAll(nextEpisodes);
-      session.remapCurrentIndex(
-        keepIndex,
-        preloadIndex: nextVisibleIndex(keepIndex),
-      );
-      _jumpToFeedPage(keepIndex);
-      notify();
-      return;
+    if (!_feedUpdateRunning) {
+      _feedUpdateFuture = _drainFeedUpdates();
+      unawaited(_feedUpdateFuture);
     }
-    _replaceSession(nextEpisodes, keepIndex >= 0 ? keepIndex : 0);
   }
 
   PlaybackSession _createSession(
@@ -222,7 +220,77 @@ class PlayerLogic extends ChangeNotifier {
     );
   }
 
-  void _replaceSession(List<Episode> nextEpisodes, int targetIndex) {
+  Future<void> _drainFeedUpdates() async {
+    _feedUpdateRunning = true;
+    while (true) {
+      if (!_hasPendingFeed) {
+        _feedUpdateRunning = false;
+        return;
+      }
+      _hasPendingFeed = false;
+      final revision = feedRevision;
+      final dramas = _latestFeed;
+      final keepDramaId = _latestKeepDramaId;
+      final resetToFirst = _latestResetToFirst;
+      if (revision != feedRevision) continue;
+      await _applyFeedUpdate(
+        dramas,
+        keepDramaId: keepDramaId,
+        resetToFirst: resetToFirst,
+        revision: revision,
+      );
+    }
+  }
+
+  Future<void> _applyFeedUpdate(
+    List<Drama> dramas, {
+    required String? keepDramaId,
+    required bool resetToFirst,
+    required int revision,
+  }) async {
+    if (!_started || revision != feedRevision) return;
+    final currentId = currentDramaId;
+    final nextQueue = PlaybackQueue.home(dramas);
+    final nextVisible = List<int>.generate(nextQueue.length, (index) => index);
+    final nextEpisodes = [for (final entry in nextQueue.entries) entry.episode];
+    feedDramas = dramas;
+    queue = nextQueue;
+    visibleIndices = nextVisible;
+    if (dramas.isNotEmpty) pageDrama = dramas.first;
+    if (nextQueue.length == 0) {
+      session.setRouteVisible(false);
+      notify();
+      return;
+    }
+    final keepIndex =
+        !resetToFirst && keepDramaId != null && keepDramaId == currentId
+        ? nextQueue.entries.indexWhere((entry) => entry.drama.id == keepDramaId)
+        : -1;
+    if (keepIndex >= 0 && session.active != null) {
+      sessionEpisodes
+        ..clear()
+        ..addAll(nextEpisodes);
+      session.remapCurrentIndex(
+        keepIndex,
+        preloadIndex: nextVisibleIndex(keepIndex),
+      );
+      _jumpToFeedPage(keepIndex);
+      notify();
+      return;
+    }
+    await _replaceSession(
+      nextEpisodes,
+      keepIndex >= 0 ? keepIndex : 0,
+      revision: revision,
+    );
+  }
+
+  Future<void> _replaceSession(
+    List<Episode> nextEpisodes,
+    int targetIndex, {
+    required int revision,
+  }) async {
+    if (revision != feedRevision) return;
     final factory = _sessionFactory;
     final coordinator = _sessionCoordinator;
     if (factory == null || coordinator == null) return;
@@ -232,12 +300,14 @@ class PlayerLogic extends ChangeNotifier {
     trackedPlayer = null;
     trackedEpisode = null;
     trackedDrama = null;
-    session = _createSession(factory, coordinator);
-    session.setRouteVisible(active && visibleIndices.isNotEmpty);
-    unawaited(previous.close());
-    _jumpToFeedPage(targetIndex);
-    unawaited(selectEpisode(targetIndex));
+    final nextSession = _createSession(factory, coordinator);
+    session = nextSession;
+    nextSession.setRouteVisible(active && visibleIndices.isNotEmpty);
     notify();
+    await previous.close();
+    if (revision != feedRevision || !identical(session, nextSession)) return;
+    _jumpToFeedPage(targetIndex);
+    await selectEpisode(targetIndex, revision: revision);
   }
 
   void _jumpToFeedPage(int index) {
@@ -625,15 +695,24 @@ class PlayerLogic extends ChangeNotifier {
     );
   }
 
-  Future<void> selectEpisode(int index) async {
+  Future<void> selectEpisode(int index, {int? revision}) async {
+    final feedRevisionAtStart = revision ?? feedRevision;
     final request = ++pageRequest;
     cancelScrub();
     // Capture the old position synchronously, persist without blocking a swipe.
     unawaited(saveCurrentProgress());
-    if (request != pageRequest || !isMounted()) return;
+    if (request != pageRequest ||
+        feedRevisionAtStart != feedRevision ||
+        !isMounted()) {
+      return;
+    }
     // 起播前先要票据：拿不到就不起播，交给三态 UI 提示（失败可重试）
     final ready = await ensureTicket(index);
-    if (request != pageRequest || !isMounted()) return;
+    if (request != pageRequest ||
+        feedRevisionAtStart != feedRevision ||
+        !isMounted()) {
+      return;
+    }
     if (!ready && ticketError != null) return;
     await session.select(index, preloadIndex: nextVisibleIndex(index));
   }

lib/pages/player/player_view.dart

@@ -2,7 +2,6 @@
 
 import 'dart:async';
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:provider/provider.dart';
@@ -131,20 +130,25 @@ class _PlayerPageState extends State<PlayerPage>
   void didUpdateWidget(covariant PlayerPage oldWidget) {
     super.didUpdateWidget(oldWidget);
     logic.attach(widget, isMounted: () => mounted);
+    final channelChanged = oldWidget.feedChannel != widget.feedChannel;
+    final feedChanged =
+        _feedSignature(oldWidget.feedDramas) !=
+        _feedSignature(widget.feedDramas);
     if (widget.homeMode &&
         widget.feedDramas != null &&
-        (!listEquals(oldWidget.feedDramas, widget.feedDramas) ||
-            oldWidget.feedChannel != widget.feedChannel)) {
+        (feedChanged || channelChanged)) {
       logic.updateFeed(
         widget.feedDramas!,
-        keepDramaId: oldWidget.feedChannel == widget.feedChannel
-            ? logic.currentDramaId
-            : null,
+        keepDramaId: channelChanged ? null : logic.currentDramaId,
+        resetToFirst: channelChanged,
       );
     }
     logic.onPageUpdated(oldWidget);
   }
 
+  String _feedSignature(List<Drama>? dramas) =>
+      dramas == null ? '' : dramas.map((drama) => drama.id).join('|');
+
   @override
   void didChangeDependencies() {
     super.didChangeDependencies();

test/core/data/services/home_feed_controller_test.dart

@@ -95,26 +95,109 @@ void main() {
     controller.dispose();
   });
 
-  test('should_ignore_stale_response_when_channels_switch_quickly', () async {
-    final anime = Completer<FeedPage>();
-    final live = Completer<FeedPage>();
+  test(
+    'should_cache_both_channels_when_responses_complete_out_of_order',
+    () async {
+      final anime = Completer<FeedPage>();
+      final live = Completer<FeedPage>();
+      final animeRefresh = Completer<FeedPage>();
+      final repository = _ScriptedFeedRepository()
+        ..enqueue(() => anime.future)
+        ..enqueue(() => live.future)
+        ..enqueue(() => animeRefresh.future);
+      final controller = HomeFeedController(repository);
+
+      final animeLoad = controller.selectChannel(HomeFeedChannel.anime);
+      final liveLoad = controller.selectChannel(HomeFeedChannel.live);
+      live.complete(FeedPage(dramas: [_drama('live')]));
+      await liveLoad;
+      anime.complete(FeedPage(dramas: [_drama('anime')]));
+      await animeLoad;
+
+      expect(controller.channel, HomeFeedChannel.live);
+      expect(controller.dramas.single.id, 'live');
+      await controller.selectChannel(HomeFeedChannel.anime);
+      expect(controller.dramas.single.id, 'anime');
+      animeRefresh.complete(FeedPage(dramas: [_drama('anime-refresh')]));
+      await pumpEventQueue();
+      expect(controller.dramas.single.id, 'anime-refresh');
+      controller.dispose();
+    },
+  );
+
+  test('should_retry_automatically_when_returning_to_failed_channel', () async {
     final repository = _ScriptedFeedRepository()
-      ..enqueue(() => anime.future)
-      ..enqueue(() => live.future);
+      ..enqueue(() async => throw StateError('offline'))
+      ..enqueue(() async => FeedPage(dramas: [_drama('live')]))
+      ..enqueue(() async => FeedPage(dramas: [_drama('anime-retry')]));
     final controller = HomeFeedController(repository);
 
-    final animeLoad = controller.selectChannel(HomeFeedChannel.anime);
-    final liveLoad = controller.selectChannel(HomeFeedChannel.live);
-    live.complete(FeedPage(dramas: [_drama('live')]));
-    await liveLoad;
-    anime.complete(FeedPage(dramas: [_drama('anime')]));
-    await animeLoad;
+    await controller.selectChannel(HomeFeedChannel.anime);
+    expect(controller.lastError, contains('offline'));
+    expect(controller.loadingFirstPage, isFalse);
 
-    expect(controller.channel, HomeFeedChannel.live);
-    expect(controller.dramas.single.id, 'live');
+    await controller.selectChannel(HomeFeedChannel.live);
+    await controller.selectChannel(HomeFeedChannel.anime);
+
+    expect(controller.dramas.single.id, 'anime-retry');
+    expect(repository.calls, hasLength(3));
     controller.dispose();
   });
 
+  test('should_not_report_first_page_loading_without_inflight_request', () {
+    final controller = HomeFeedController(_ScriptedFeedRepository());
+
+    expect(controller.loaded, isFalse);
+    expect(controller.loadingFirstPage, isFalse);
+    controller.dispose();
+  });
+
+  test('should_finish_loading_with_error_when_request_times_out', () async {
+    final pending = Completer<FeedPage>();
+    final repository = _ScriptedFeedRepository()..enqueue(() => pending.future);
+    final controller = HomeFeedController(
+      repository,
+      requestTimeout: const Duration(milliseconds: 10),
+    );
+
+    await controller.selectChannel(HomeFeedChannel.anime);
+
+    expect(controller.loadingFirstPage, isFalse);
+    expect(controller.loaded, isTrue);
+    expect(controller.lastError, isNotNull);
+    controller.dispose();
+  });
+
+  test(
+    'should_ignore_old_failure_when_same_channel_new_request_succeeds',
+    () async {
+      final oldRefresh = Completer<FeedPage>();
+      final repository = _ScriptedFeedRepository()
+        ..enqueue(
+          () async => FeedPage(
+            dramas: [_drama('a')],
+            nextCursor: 'next',
+            hasMore: true,
+          ),
+        )
+        ..enqueue(() async => FeedPage(dramas: [_drama('live')]))
+        ..enqueue(() => oldRefresh.future)
+        ..enqueue(() async => FeedPage(dramas: [_drama('b')], hasMore: false));
+      final controller = HomeFeedController(repository);
+      await controller.selectChannel(HomeFeedChannel.anime);
+      await controller.selectChannel(HomeFeedChannel.live);
+      await controller.selectChannel(HomeFeedChannel.anime);
+
+      await controller.loadMore();
+      oldRefresh.completeError(StateError('old failure'));
+      await pumpEventQueue();
+
+      expect(controller.dramas.map((drama) => drama.id), ['a', 'b']);
+      expect(controller.lastError, isNull);
+      controller.dispose();
+    },
+  );
+
   test('should_keep_old_data_when_refresh_fails', () async {
     final repository = _ScriptedFeedRepository()
       ..enqueue(() async => FeedPage(dramas: [_drama('old')]))

test/player/player_logic_test.dart

@@ -431,7 +431,7 @@ void main() {
       final activeBefore = logic.session.active;
 
       logic.updateFeed([...feed, _drama('third')], keepDramaId: 'signal');
-      await pumpEventQueue();
+      await logic.feedUpdateSettled;
 
       expect(logic.currentDramaId, 'signal');
       expect(logic.visibleIndices, [0, 1, 2]);
@@ -463,7 +463,7 @@ void main() {
         [_drama('city'), _drama('signal'), _drama('third')],
         keepDramaId: 'city',
       );
-      await pumpEventQueue();
+      await logic.feedUpdateSettled;
 
       expect(logic.currentDramaId, 'city');
       expect(logic.session.currentIndex, 0);
@@ -488,7 +488,11 @@ void main() {
       logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
       await _drain(logic);
 
-      logic.updateFeed([_drama('anime-a'), _drama('anime-b')]);
+      logic.updateFeed(
+        [_drama('anime-a'), _drama('anime-b')],
+        resetToFirst: true,
+      );
+      await logic.feedUpdateSettled;
       await _drain(logic);
 
       expect(logic.queue.entryAt(0).drama.id, 'anime-a');
@@ -517,6 +521,7 @@ void main() {
       await _drain(logic);
 
       logic.updateFeed(const []);
+      await logic.feedUpdateSettled;
 
       expect(logic.queue.length, 0);
       expect(logic.visibleIndices, isEmpty);
@@ -524,6 +529,95 @@ void main() {
       logic.dispose();
       await _drain(logic);
     });
+
+    test('should_apply_only_latest_feed_when_update_is_called_five_times',
+        () async {
+      final factory = _RecordingFactory();
+      final logic = _logic(FakeWatchHistory());
+      final initial = [_drama('initial')];
+      logic.attach(
+        PlayerPage(
+          drama: initial.first,
+          initialIndex: 0,
+          homeMode: true,
+          feedDramas: initial,
+        ),
+        isMounted: () => true,
+      );
+      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
+      await _drain(logic);
+
+      for (var index = 1; index <= 5; index++) {
+        logic.updateFeed([_drama('feed-$index')], resetToFirst: true);
+      }
+      await logic.feedUpdateSettled;
+      await _drain(logic);
+
+      expect(logic.feedRevision, 5);
+      expect(logic.queue.entryAt(0).drama.id, 'feed-5');
+      expect(logic.sessionEpisodes.single.id, 'feed-5-1');
+      expect(logic.currentDramaId, 'feed-5');
+      logic.dispose();
+      await _drain(logic);
+    });
+
+    test('should_select_first_item_when_feed_recovers_from_empty', () async {
+      final factory = _RecordingFactory();
+      final feed = [_drama('signal')];
+      final logic = _logic(FakeWatchHistory());
+      logic.attach(
+        PlayerPage(
+          drama: feed.first,
+          initialIndex: 0,
+          homeMode: true,
+          feedDramas: feed,
+        ),
+        isMounted: () => true,
+      );
+      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
+      await _drain(logic);
+      logic.updateFeed(const []);
+      await logic.feedUpdateSettled;
+
+      logic.updateFeed([_drama('restored')], resetToFirst: true);
+      await logic.feedUpdateSettled;
+      await _drain(logic);
+
+      expect(logic.queue.entryAt(0).drama.id, 'restored');
+      expect(logic.session.currentIndex, 0);
+      expect(logic.currentDramaId, 'restored');
+      expect(factory.live, greaterThan(0));
+      logic.dispose();
+      await _drain(logic);
+    });
+
+    test('should_reset_to_first_when_channel_changes_with_same_ids',
+        () async {
+      final factory = _RecordingFactory();
+      final feed = [_drama('same-a'), _drama('same-b')];
+      final logic = _logic(FakeWatchHistory());
+      logic.attach(
+        PlayerPage(
+          drama: feed.first,
+          initialIndex: 1,
+          homeMode: true,
+          feedDramas: feed,
+        ),
+        isMounted: () => true,
+      );
+      logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
+      await _drain(logic);
+      expect(logic.session.currentIndex, 1);
+
+      logic.updateFeed(feed, resetToFirst: true);
+      await logic.feedUpdateSettled;
+      await _drain(logic);
+
+      expect(logic.session.currentIndex, 0);
+      expect(logic.currentDramaId, 'same-a');
+      logic.dispose();
+      await _drain(logic);
+    });
   });
 
   group('lifecycle', () {